Millions of laboratory animals are used every year in experimental research. These animals range in size from mice to non-human primates. In order to conduct valid and reliable experiments, researchers must be assured that their animals are protected from pathogens and microbial contaminants that will affect test results and conclusions. Guide for the Care and Use of Laboratory Animals, (1985) U.S. Department of Health and Human Services, NIH Pub. No. 82-23.
Many laboratory animals have subclinical infections, in which they do not demonstrate any overt signs of disease. Because more research is now being conducted at the molecular and microscopic level, these subclinical infections are being discovered and are invalidating research. Orcutt, R. P. (1987) How to Conduct Rodent Research Free of MHV, Sendai Virus, and Other Pathogens, Lab Animal. May/June. Bhatt, P. N. et al, eds. (1986) Viral and Mycoplasmal Infections of Laboratory Rodents, Effects on Biomedical Research, Academic Press, Orlando, Fla. Parker, J. C., Whiteman, M. D. and Richter, C. B. (1978) Susceptibility of Inbred and Outbred Mouse Strains to Sendai Virus and Prevalence of Infection in Laboratory Rodents, Infection and Immunity. 19:123-130. These and other studies demonstrate that contamination and compromised animal integrity is a pervasive problem in the United States. The loss of biological integrity results in significant losses in valuable research time and money in laboratory animal research.
In addition to protecting animals from extraneous contamination, there is a need to isolate laboratory personnel from allergens that are indigenous to a species or hazardous agents that are experiment specific. For example, many technicians and scientists are troubled by allergic reactions to animal dander. There is also the threat of contracting contagious diseases that are present in animal studies.
Over the past two decades, the animal industry has made great strides in trying to solve these contamination problems. Most of this change has been a result of higher standards of health, imposed by various governmental agencies and regulatory groups. Parker, J. C. (1980) The possibilities and limitations of virus control in laboratory animals, pp. 161-172 in Animal Quality and Models in Bio-medical Research. A. Spiegel, S. Erichsen, and H. A. Solleveid, eds. New York: Gustav Fischer Verlag. Breeders use elaborate barrier systems for breeding, and produce animals that range in biological integrity from some type of specific pathogen free mice to gnotobiotic mice. Breeders also have barrier systems for hamsters, gerbils, guinea pigs and larger laboratory animals. Unfortunately, most research facilities do not have elaborate containment systems required to maintain biological integrity and animals can become contaminated at the research facility or in transit, where they are exposed to the open environment.
The current technology to isolate small laboratory animals in research facilities consists of filtered air hoods, filtered air housing units and filtered air rooms. These systems are very expensive and are stationary in nature. There is currently a trend towards the use of micro-isolator cages, in which only the food, bedding, etc. have to be changed in filtered air hoods. The most common filter media used in the laboratory animal industry is a spunbonded polyester, Reemay.RTM. 2024. It has an 85% atmospheric dust removal efficiency for particles in the 1 to 5 micron range but only a 28% efficiency for particles in the 0.3 to 1 micron range. Atmospheric Duct Efficiency (ASHRAE Test Duct--Coulter Counter), (1988) REEMAY For Air Filtration Sales Literature, Snow Filtration Company. Also available are micro-barrier containers that are constructed of pressed pulp. The pressed pulp forms a dense mat of wood fibers that acts as a depth filter to block the passage of microbial contaminates. Tanner Products, Co. St. Louis, Mo.
It is therefore an object of the present invention to provide a method and means for isolating animals in transit, as well as in the laboratory, from bacteria, viruses, and other pathogenic or potentially pathogenic agents.
It is further object of the invention to provide a means for protecting animals in transit, and those exposed to them, at minimal expense and effort.
It is a still further object of the present invention to provide a means for protecting and isolating animals in transit from environmental agents while allowing free exchange of gases without building up excessive temperatures within the animal facilities.